Selective signaling system



May 2, 1950 J. M. MELlcK SELECTIVE SIGNALING SYSTEM 2 Sheets-Sheet 1 Filed May 51, 1946 INCOMING lv LINK J'UBJ'CR/BEH'J" REGISTER .SE/VDE@ VVE/WOR J M MEL /CK ATTORNEY May 2, 1950 J. M. MELlcK 2,506,429

` SELECTIVE SIGNALING SYSTEM Filed May 3l, 1946 2 Sheets-Sheet 2 CONTROL RELYS AREG/STER 9 Ilia- TO NEX T SET 0F REG/STER RELYJ /NVENTOR J M MEL /CK MWC@ ATTORNEY Patented May 2, 1950 UNITED ATENT orales Telephonek Laboratories,

Incorporated, N elw York, Yr., a, @Epuration f,A New Yui'k Awnangn 1946, serial'No. 673,276

(o1. 17a-fan).

Claims. lV

rlhis invention relates to signaling systernsand particularly to selective sig-naling'adapted for use in automatic telephone systens.

O biqGts of the invention are an increase in the speed and enciency o -i seectiye signaling automatik; tslsniisn'srsttnis. "and 'ssii'rall't "tlis provision of new and irn-proyed Vselctiye signaling arrangements.. *A l -Hereto'fore selective signaling systems ha-Ve been arranged to transmita plnrality kif-diff rent signes by usine Currents Qitiiiiitntaintlitiids 9i Palaiity tagatlier with. marginal. anti ntlatlatl signal receiving relays, t9 transmit siiiigtisnt number of sncssssiva entrent iiniiiilsss .for aa la @inerenti signal, and t0 transmit alternating urreni of different irequensy or ninas@ iai, aatli different .sienal-` It. is also linawn t9.- llse, botti direct and altar-nati.naA surfant isi saltati@ slsf naling. i v *Y This invention is a signalingv systani. arranged sn. that tina transniilssan ai @aan 'ai a iilllralitr of disaient telecine seais is tainted ,une transmission of one, two or thrss an` ini: nnlss'sy sash, iinnnlsa latina aithlsr .finest @tirant or .alternating current .Sinne 9i this@ ininulsas is required far any signal, all. 9i the digits of a called subscribers nunl r Inay be transmitted in a short interval of tune. and, by providing key-set signal transmitters at'th'e subscribers stations, the signal irnpulses a transmitted with minimum sinit .and mania-itin accuracy.

A feature af the invention is a selettiva signal Y transmitter arranged '.00. 1lrarlsirlit signals sisting of either one, tyto Orthree irnp s in 4 t or succession, each irnpnlse being either di alternating current, andv arranged s o that open-,circuit condition precedes the @rst impulse .f each selective signal to prepare 'the si ceiving means for responsa t0 tira ininnlss 9i pulses which asnstituts the ,selettiva sia'iial @eine transmitted.

A clear and @Qinltlsts lliidsistaiiditl Qi the invention. will be iaiiitatad by ainsiilsfinal 'a signaling .system arranged, lll @ST/@Qltalle Wil?? the invention and its features, tins sutil svsttin being represented ,sliainfatitally .in tits, drawing, Wliitli slonssts 0f two fisuras- 'llle inventisisl hawaiian not. limited in its annlitation to the specific system ai apparatus stint/ii, in the drawine but is anpiisabie' t0 selettive signalingl srsteinsf asnaially- `f The drawing represents 'anY autornatig telephone system comprising vswitchesY ofthe cross barir type and register senders for controlling the establishment of desired connections between calling and called subscriber stations.

lig. 1 of the drawing shows a calling subscribersv station Iii, a key-Set KS for'transr'nitting selective signals, a line link il@ and sender link 50 of the cross bar type, a district 5t), incoming "iQ, and a called subscribers station Se. Fig. 1 further shows, together with Fig.. 2, a subscribers register sender lili)v adapted to receive and register seleotive Ysignals transmitted from a connected calling subscribers' station such as the station it.

subscribed station l is ofthe type usually proyidedy for use with co'ininon battery central oiicesencept 'that' the signal sender is of the key-set type.V Themley-set KS comprises a plurality oi keys,` oneffor Heach of the' selective signals which `rnay be transmitted and contact sp' 2st, 2 6, `3i and 32. 4c 'onirnofn toall of the keys. key consists of a button 20 which ,naar lia isaiassti against the tension '0i a Sistina' 2l.l When all keys are in normal position, the contant g3 is` closed, and contacts 25,135Y 32 are finan 'lis 's QOn asa key isninvsi ont @i nornial position', contact 23 is opened and, just before the lgefy reaches the limit of its motion, theprojectigon'g engagesfthe'c'arn 25 and rotary rnovernent o f carri 25 Mcloses 'ornact ZtfContact g3 relnains'open and contact 2Sneniains closed until themkey is restoredl to normal, at which tine' prlectin 22vk closes contact 23 and projecgil' restores caln to normal thereby opening Contact g5. When the key has been'fully depressed and the pressure on'button Ze is re'- rnoil'ed, the contacts 3| and 32 are actuated by the key surface 2l, 284, 2S to establish impulse circuits" through condenser fandind-uctance 352 as required to transmit signalinpulses indicative ofthe particular key which isdepressed. Although' actuated by the dowmstroke' of the key aswell as'by the Lip-stroke, contacts Si and 32 are ineffectiye to transmit signal iimoulsesvv dur-l ing the down-stroke due tothe fact that contact 25 is not closed until the key is depressed far enough to actnate loam 25. "ihenimpuls'e controlling surface of each key is Ydii-ie'reritly shapedfso that adilierent signal will be initted by the operation of each key. An out rigardly projecting portion of the surfaceg such as 21'01" effectsy closure of contact 32 and a depression, such as 28, effects closure @i cont-act 11 'iljhe contacts 23, 2e, 3i 4.and 32 are common to all f the keys and only one key can be depressed at a time. The key shown is shaped so that on the release of button 20, contact 32 will close rst to transmita signal impulse through inn ductance 30, contact 3| will close neXt to transmit a signal impulse through condenser 33, and contact 32 will then again close to transmit another signal impulse through inductance 34. As hereinafter explained, each closure of contact 32 effects the transmission of a direct current signal impulse through inductance 34 and each closure of contacts 3| eifects the transmission of an alternating current signal impulse through condenser 33. Fourteen different signals may be transmitted by providing fourteen different keys, the signal controlling surface of each key being shaped to transmit either one, two or three signal impulses as indicated in the table concluding the description of the system shown in the drawing.

While the keys are all normal, a direct current circuit is closed through contact 23 but this circuit is opened at contact 23 by depressing any key so that an open-circuit condition exists immediately prior to the first signal impulse of each of the fourteen different signals. If decimal signaling is desired, any ten of the fourteen different signals may be used.

The signal receiving means in the register sender comprises a battery or other direct current source connected to one winding of coil |03, an alternating current source |013 connected to the other winding of coil |03, two relays and |06, a rotary distributor D, and three sets of impulse relays, |3| and |32, |ll| and |102, and |5| and |52. The register sender further co l-- prises a set of register control relays for each digit transmitted and a set of register relays for each digit. Relays 20| and 202 constitute the register control relays which render the relays 2| 2|2, 22|, 222, 23| and 232 of the Aregister operatively responsive to the signal impulses representing the rst digit of a called subscribers number. A similar set of register control relays and register relays is provided for each digit to be registered.

The rotary distributor D is of the start-stop type well known in telegraph systems and reference may be had to the patent to E. F. Watson 2,055,567, granted September 29, 1936 for a disclosure of such a distributor. The distributor D comprises a control magnet and two distributor brushes B| and B2 iixed to a common shaft which is arranged to make one revolution each time the energization of magnet l releases the stop cam ||2. The functions of the distributor will be apparent from the following description of the transmission and registering of a digit responsive to operation of one of the keys at a connected calling subscribers station i0.

Assume now that a call is initiated at station |0 by removal of the handset thereby actuating switch |2 to close a loop circuit over the conductors of line L. Assume further that a line link 40 is actuated to extend the line LI to an idle district 50 and that a sender link 60 is actuated to connect the district 50 to an idle register sender |00. Reference may be had to the patent to Carpenter 2,235,803, granted March 18, 1941, for a complete disclosure of a switching system in which line links and sender links of the cross bar type are provided for connecting a calling line through a district to a subscribers register sender. Upon completion of the connection between line Ll and the register sender |00, a circuit is closed from battery through the left winding of coil |03, conductor |02, through the link 00, district 50, and line link 00, one conductor of line Ll, left winding of coil I3 at station |0, transmitter of handset lower contact of switch i2, contact 23 of the key-set KS, other conductor of line L|, through link 40, district 50, link 00, conductor |0|, winding of relay |05, conductor |09, feed ring |20 and brush B2 of distributor D to grounded segment |25. Relay |05 is operatively energized by the current in this circuit, closing a circuit for operating the slowto-release relay |00. Relay |00 is eiective to maintain the connection through link 00 in usual manner. The operation of relay |00 connects ground to conductor. |01 and closes a circuit through the right winding of coil |03 and alternating current source |00, whereby alternating current is superimposed on the direct current transmitted over the calling line loop circuit above traced. The alternating current from source |04 may also serve as the dial tone signal to indicate that dialing may be started. When the calling subscriber depresses the key corresponding to the first digit of the call subscribers number, the calling line loop is opened at contact 23 thereby causing the release of relay |05. The release of relay |05 connects conductor |0| through the upper back contact of relay |05 and outer front contact of relay |00, feed ring |24 and brush B| and segment |20 of distributor D, and through f-ull wave rectiiier l0 and the winding of magnet to ground. When the key reaches the limit of its down-stroke, cam 25 is actuated by the projection 22 to close contact 26; and when the one or the other of contacts 3| and 32 is actuated at the beginning of the upstroke of the key, magnet is operated by the rst current impulse to release stop cam i2 and thereby start the rotation of the shaft of the distributor D. Relay7 |05 does not reoperate since its winding is shunted by the winding of magnet I. If necessary, a relay may be added to open the circuit path through the winding of relay |05 responsive to the release of relay |05, thereby insuring the operation of magnet without reoperating relay |05 responsive to the iirst current impulse of a signal. When brush B! disengages segment |20, magnet releases so that the armature will stop the shaft from further rotation when one revolution is completed. The rate of rotation of distributor D and length of segment |2|, is such that brush Bl will be in contact with segment |2| for substantially the same interval of time that contact 3| or contact 32 of the key-set KS is actuated to include either condenser 33 or inductance 30 in series with contact 26 and the conductors of line L| to transmit the iirst impulse of the signal corresponding to the iirst digit of the called subscribers number. It is to be noted that the upper projection 21 of the impulse controlling surface of key 20 is longer than the depression 28 and lower projection 29 so that the iirst impulse of a digit signal is longer than the second and third impulses in order to provide time for operating the magnet of the distributor, for rotating brush B| into engagement with segment |2| and for operating one of impulse relays i3! and |32, while brush B| is in engagement with segment |2|. The rate at which key 20 is restored to normal is such that the second impulse of a digit signal is transmitted while brush BI is in engagement with segment |22 and the third impulse is transmitted while brush Bl is in engagement with segment |23.

it-.comet duration of the. closure of contacts 3|- and 32 may be approximately as follows:

lf dllrg the time' brush Bi S ill engagement With Segment, lill'. Contact k3.2 oi key-'sei KS is Closed'. the inclusion of iriclu ctan'cjey itil'v in' series with' cone tact 2li and line Ll effects the transmission oi' a directl current impulse over the line through the upper back` Contact of relay m5, iront contact of relay |08,y feed ring |-24, brush Bi, segment |2| and 'Winding of relay |^32to ground,` thereby oper'- ating relay |32. Rectifier |30` is poled to prevent.

the' energization of relay |3|. I'fl, however, the impulse control sur-face oi key 2t is shaped so that contacts 3|E are closed While brush Bl is inl ene gagementwith segmentl |2|, the condenser Sie is included in the line loop circuit instead of inducte ance 34 and the alternating current voltage induced in coil iii-'3 effects the transmission of alter-A nating current in the line loop circuit through contacts 26, condenser 33', contact 3|, over line L'| through brush Bl and segment |21 to the windings of relays |3t and |32. Relay i32- is not operatively energizedY by alternating current but halfl cycles are transmittedtlirougii recti-er |39 to' effect the operative energization of the upper windingof relay |3,|. Thus either relay |3| or relay i352 is operated responsive tQ the first irn-r pulse of a digit signal depending upon Whether the line loop circuit'igs closed through indu'ctance se or condenser 33'. The operated one oi relays and |32 locks through its lower Winding to grounded conductor Hitt. By the` time brush Bl' has advanced to engage" segment i212.. the key 2 6 Will have TGSQT'QAF. Slenty SO that' f. thee lS more, than one. impulse in the digit sieuel' beine transmitted. the impulse surface' of' the key will' have.' actuated either Contact 3,2' or Contact' el: to' eilect the transmission o f either aA direct current impulse or alternating current impulse oyer iiue lili. depending' onf the particular digit being trausriliitui Siriee segment` |22k is Connected. to relays f4.1 aud. |41, the, one or. the other of; these relays will be operated to register the second impulse or the digit signal being transmitted. The operated one of relays M l and |ri2 locks through its lower winding to conductor |08., When brush BI engages segment |23; the key 2li will have restored suiciently so -that if there is more than two impulses in the digit signal being transmitted, the impulse surface of the key 2Q Will have actuated either Contact 32 or Contact 3|' to effect the transmission of either a direct current impulse or an alternating current impulse Aever line lill depending on the particular digit being transmitted. Since segment |23 is connectedI to relays |5| andv |52, the one or the ether of` these relays will be operated to register the third impulse of the digit signal being transmitted. The operated one ofV relays |5| and' i522 I 'qcli through its loWer'Winding to conductor |08. Thus the signal transmitted by the operation of a particular key corresponding to the r'st digit of the called subscribers' number effectsr the operae tion oi eitherv relay lil or relay i3'i eloiie, the operation of either relay |3| or relay |32V and the operation of either relay mi cr'relay- 42, or; the operation of either?r relay #3i or relay' |32 and the operation or either relay IMI die rel'ay' |42 and the operation of either' relay [5t ori relay 52', 5 dependingupon the numerical value of the digit being transmitted. y y Relay |05 remains deen'ergized While the distributoris receivingthe signal'- impulses corresponcii'rlg` to the first digit since the circuit for operating relay m5 is; ope-n as soon as brush-B1 advancedI sufjciently to disengag'e segment and the' operating' path through brush Bzand segment 525 is not again closed until sufficient time has elapsed for three signal impulses tc'ijli'ave been received, at Which time brush Bl; will' have passedf beyond seg-ment |23.- Wlien the key dpressecl to transmit the rst digitJ reaches normal, contacts 2t arev opened and contacts 2 3 are closed; and, with brushV B2 then in engagement with segment |25, the line loop circuit is closed tc reoperate relay it before brush Bl again eri-4 gages segment |20. The reoperati'on of relay |65 recloses the circuit for energizing relay |!l6 relayk |08 remaining operated While eaclfindigit signal is, being received- The rejoperation oi'reiay |05 else. disconnects ground' from. conductor |08 te ,release any of relays lei. raz, les, riz. ieri and (5.2 which Were operated resionsire' to the iirst digit.sierlel-` 'rior to the, release of. these relays. the -rst digit will have been registered by than register' as hereilueiter desloriloedthe, key corresponding to the second. digit of the called subsoribers, number is depressed., the above-rief scribed cycle of Qperations'- is repeated tp, effect they selective operation of relays iai, isz, lll. |42, lei and |52, according to the value of this digit.. lo. like marmer each of the succeeding dietits, of the Called subscribers number trellis.- mite'd over line Ll to eiiect the selective opere.- iicn of these relays, the` distributor D, making one revolution for' each digit,

When relay i3! or relay |32 is operated respon: sive to the first signal impulse of the first. digit signal. transmitted from e call-ine station, cio-und connected tor one, of eouduetof's |35.. and lili depending on which one of these relays is up-` erated. arid crouriel is` also ooiuieoteci to. conductor iti bly. the operation of either one of relays i'ei and |32. If relay' I3! is operated, a circuit is closed for operating relay 2| l of the A register; or, if relay i252 is operated, a circuit is closed for opeerating relay l2 of the A register. The operated one of relays 2H and 212 locks until the register sender is released or the registered information has been utilized'. If one of relays Mui |452 is operated responsive to al secondsignal;y impulse for the. nist digit. ground: is. connected her to conductor M5 or to conductor |46 toi oie ete relay 22! or relay 22:2, oit the A. register, And ii' one of relays |51' and |152 is operated re. sponsive to a third Signal Simpulse for the` digit, ground is connected either toconductor |55; or to; conductor lee toy operate relay 23| or relay 232v of the i regi "l The. aforementioned ccnl, f ne'ction oi ground to conductor |31 causes the operative energization of register control relay 2M; Relay 2U connects its WindingA in series With the winding or relay 28.2 to` grounded conductor- !'i' but the Winding of relay 202 is shortecircuited as long as ground is connected: to con--V ductoi i3?. relay. '55 reoperates as above described at the end of the rst digit signal; ground isv disconnected frorn conductor lll'and ine operated ones or reiays ist, isz, mi, |42, 'iii' and 52 release; aridi grlihel is thereby (11S,-

connected from conductors |35, |36, |31, |45, |46, |55 and |56. The disconnection of ground from conductor |31 opens the short-circuit across the winding of relay 202 so that relay 2321s now operatively energized in series with the winding of relay With relay 202 operated, conductors |35, |36, |31, |45, |46, |55 and |55 are extended to the B register control relays and B register, which are similar to the A register control relays and A register. Thus the selective operation of relays |3|, |32, |4|, |42, |5| and |52 responsive to the signal impulses transmitted by the depression of the key corresponding to the second digit of the called number eiects the registration of this digit by the operation of one or more of the B register relays. In like manner, the succeeding digits of the called number are transmitted to selectively operate relays |3|, |32, |4I, |42, |5| and |52 and effect the registration of the digit by the relays of a corresponding register.

The selective operation of the register relays of the A register and each of the other registers establishes circuit conditions representing any one of digits 0 to 9 and four additional circuit conditions representing four other signals which the key-set KS is capable of transmitting. The manner in which the registered information is to be used will determine the control established by these fourteen circuit conditions. Assuming that individual digit registers are provided for each numerical value, two such registers il and 9 are shown. The circuit for operating register i! is traced from ground at the armature of relay 2 2, back contact of relay 2|2, front contact of relay 2| l, back contacts of relays 22| and 222 and back contacts of relays 23| and 232 to battery through the winding of register The circuit for operating register 9 is traced from ground at the armature of relay 2|2, back contact of relay 2|?, front contact of relay 2| l, front contact of relay 222, back contact of relay 22|, fro-nt Contact of relay 232 and back contact of relay 23| to battery through register 9.

The following table shows the fourteen diierent signals, the signal impulses corresponding thereto, the corresponding r-elays which are operated responsive to the signal impulses and the register relays operated to register the various signals:

Signal Impulses Signal Signal Relays I'ielasgr Operated O t d ist 2nd 3rd Dem e A. C. 131 211 D. C. 132 212 A. C. A. C. 131,141 211, 221 A. C. D. C. 131, 142 211, 222 D. C. A. C. 132,141 212, 221 D. C. D. C. 132,142 212,222 A. C. A. C. A, C. 131, 141, 151 211, 221, 231 A. C. A. C. D. C. 131,141, 152 211, 221, 232 A, C. D. C. A. C. 131, 142, 151 211, 222, 231 A. C. D. C, D. C. 131, 142, 152 211, 222, 232 D. C. A. C. A. C. 132,141, 151 212, 221, 231 D. C. A. C. D. C. 132,141,152 212, 221,232 D. C. D. C. A. C. 132,142,151 212,222, 231 D. C. D. C. D. o. 132,142,152 212, 222, 232

It is of course possible to provide for more than fourteen signals, the additional signals requiring tne transmission of additional impulses. For instance, with a maximum of four impulses per signal, thirty diierent signals may be transmitted.

What is claimed is:

1. In a signaling system in which different signals consist of either one, two or three impulses of current in succession, each impulse being either alternating current or direct current, the number of impulses and character of each impulse depending upon the particular signal being transmitted, signal receiving means comprising means or selectively responding to the first impulse of a signal depending upon whether the impulse is of one character or the other, means for selectively responding to the second impulse of a signal depending upon whether the impulse is of one character or the other, means for selectively responding to the third impulse of a signal depending upon whether the impulse is of one character or the other, a start-stop distributor with a position for each of said impulse responding means, and means responsive to the first impulse of a signal independent of the type of current for starting said distributor, thereby directing each impulse of a signal to a different one or" said selective responding means.

2. In a signaling system in which diierent signals consist of either one, two or three impulses of current in succession, each impulse being either alternating current or direct current, the number of impulses and character of each impulse depending upon the particular signal being transmitted, means for transmitting any one of said dierent signals and including means for making the rst impulse of each different signal longer than succeeding impulses of any signal, signal receiving means comprising means for selectively responding to the iirst impulse of a signal de pending upon whether the impulse is of One charz acter or the other, means for selectively responding to the second impulse of a signal depending upon whether the impulse is of one character or the other, means for selectively responding to the third impulse of a signal depending upon whether the impulse is of one character or the other, a start-stop distributor with a position for each of said impulse responding means, means responsive to the first impulse of each signal for starting said distributor thereby to direct each impulse of a signal to a different one of said selective responding means, and register means controlled by said selective responding means.

3. In a signaling system, a line, a signal transmitting station connected to said line and comprising a iirst set of contacts normally closed in series with said line, an inductance, a capacitance, a second set of contacts for connecting said inductance in series, with said line, a third set of contacts for connecting said capacitance in series with said line, a plurality of self-restoring keys one for each different signal which it may be desired to transmit over said line, the actuation of each of said keys being effective to open said rst set of contacts until the key restores to normal, and means controlled by each of said keys While being restored to normal t0 close either said second set or said third set of contacts to transmit a signal consisting of one current impulse, to close either said second set or said third set of contacts to transmit the iirst current impulse and to close either said second set or said third set of contacts to transmit the second impulse of a signal consisting of two current impulses in succession or to close either said second set or said third set of contacts to transmit the rst current impulse and to close either said second set or said third set of contacts to transmit the second impulse and to close either said second set or said third set of contacts to transmit the third impulse of a signal consisting 9 of three current impulses in succession, and signal receiving means connected to said line to selectively respond to the signal transmitted over said line by the actuation of any one of said keys.

4. A signaling system according to claim 3, said signal receiving means comprising a first relay connected in series with said line and said rst set of contacts, a second relay operated responsive to the operation of said rst relay and slow to release, a first set of relays including a relay adapted for operation by alternating current and a relay adapted for operation by direct current, second and third sets of relays similar to said rst set of relays, distributor means for connecting said line to said first set of relays while the iirst current impulse of a signal is being transmitted over said line to said second set of relays while the second current impulse of a signal is being transmitted over said line and to said third set of relays while the third current impulse of a signal is being transmitted ov-er said line, and means responsive to the release of said rst relay upon the opening of said first set of contacts at said signal transmitting station for initiating the operation of said distributor.

5. A signaling system according to claim 3, said signal receiving means comprising a first relay connected in series with said line and said first set of contacts, a second relay operated responsive to the operation of said rst relay and slow to release, a first set of relays including a relay adapted for operation by alternating current and a relay adapted for operation by direct current,

second and third sets of relays similar to said first set of relays, distributor means for connecting said line to said first set of relays While the iirst current impulse of a signal is being transmitted over said line, to said second set of relays while the second current impulse of a signal is being transmitted over said line and to said third s-et of relay while the third current impulse of a signal is being transmitted over said line, means responsive to the release of said rst relay upon the opening of said first set of contacts at said signal transmitting station for initiating the operation of said distributor, and register means controlled by said relays to register each signal transmitted over said line.

JOHN M. MELICK.

REFERENCES CITED The following references are of record in the file oi this patent:

UNITED STATES PATENTS Number Name Date 1,672,005 Sorenson June 5, 1928 2,367,522 Pfleger Jan. 16, 1945 2,381,499 Jackel Aug. 7, 1945 2,393,377 Jackel Jan. 22, 1946 2,396,134 Sorenson Mar. 5, 1946 2,400,148 Hubbard May 14, 1946 2,401,729 Goldsmith June 11, 1946 2,411,191 Burcky Nov. 19, 1946 V2,411,375 Jackel Nov. 19 1946 

